Self-Warming Container

ABSTRACT

An apparatus for warming substances comprising a container, said container including a first compartment containing a substance that reacts exothermically with water, a second compartment containing water, wherein said second compartment is attached to said first compartment by a valve, and a third compartment, wherein at least 50% of the third compartment&#39;s volume is surrounded by said first compartment, and wherein said first and third compartments are separated by a thermally conductive wall. In a preferred embodiment, the substance that reacts exothermically with water is an anhydrous zeolite.

This invention relates to systems and methods for containers that can warm their contents using an exothermic reaction, such as mixing water with anhydrous zeolites. This application claims benefit under 35 U.S.C. §120 of the filing date for application No. 61/790,297 filed Mar. 15, 2013.

BACKGROUND OF THE INVENTION

It is often desirable to be able to heat or reheat items like meals or baby bottles while on the go, away from the convenience of typical heating units such as microwaves. Many portable warming devices rely on power cords, which necessitate the availability of power outlets, to warm their contents. Other such portable warming devices rely on battery power, which have a limited life span, or electrical heating components, which present the possibility of component failure or wear out. Many “cordless” portable devices require time-consuming charging or recharging periods each time the device is used. Additionally, many such portable heating devices only warm their contents but provide no method of maintaining temperature prior to the warming process.

A novel self-warming container presents a solution to these dilemmas. The container warms its contents at the touch of a button by harnessing heat generated from an internal and enclosed exothermic reaction. To recharge the container for additional uses, one need only microwave the container for a few minutes, resetting the chemical reaction to its initial state. The container is then ready to heat its contents again minutes or even days later. The self-warming container has an array of uses, from heating food for lunches and picnics to warming baby bottles and wipes. The self-warming container can take a variety of configurations depending on its intended use. The invention is especially well suited for food storage, as the design allows it to maintain a relatively constant temperature even prior to warming. Therefore, if refrigerated, the container will keep food cool for a significant amount of time prior to warming.

BRIEF SUMMARY OF THE INVENTION

The invention is a self-warming container, which requires no outside energy input (such as power cords or batteries) to warm its contents other than the addition of water prior to use. The container will begin to warm contents at the touch of a button, so that the user has control of when the contents are to be heated. Additionally, the container only need be heated in the microwave or oven for a few minutes and the water replenished to recharge the heating capabilities of the unit before the next use of the device. In some embodiments of the invention, due to the thermal mass of the container, it could also be used to keep food at a cool temperature prior to warming, if the container is stored in a cool environment, like a refrigerator, prior to use.

To prepare the device for heating, water is added to an internal water reservoir in the container. To initiate warming, a button adjacent to the water reservoir is depressed. When the button is depressed, the water mixes with a heat producing substance. The interaction between the water and the heat-producing substance causes an exothermic reaction, and the heat is dissipated to the container to warm the contents.

To reset the heating process, the container is microwaved or placed in the oven to dehydrate the heat-producing substance, which causes the heat-producing material to “reset” itself. Water vapor escaping the container during this “resetting” is vented through a one way valve leading away from the container or is condensed back into the water reservoir. The valve seals itself so that water vapor form the ambient air cannot enter the container and inadvertently interact with the heat producing material.

There are a number of possible configurations for the invention, based on the size and type of contents to be warmed. For each configuration the method of heating is the same as detailed above. All embodiments include at least one compartment for contents to be warmed and at least one water reservoir compartment, with a surrounding thermal shell for temperature control and heating.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1. Example of one possible design of the container.

FIG. 2. Depiction of differing states of the start button.

FIG. 3. Cutout side view of internal aspects of container in FIG. 1.

FIG. 4. Two additional possible configurations and uses of the container.

FIG. 5. Schematic of internal components of container, side view.

FIG. 6. Detail of water vapor release valve and water reservoir valve.

FIG. 7. Cross-section of self-warming container with removable zeolite cartridge.

FIG. 8. Detail of cross-section of self-warming container with removable cartridge showing juncture of cartridge with water compartment.

DETAILED DESCRIPTION OF THE INVENTION Basic Design

The design of the invention can take on any number of configurations, depending on the intended use of the device. All configurations have at least the following components: an internal compartment for storing the contents to be warmed, an internal water reservoir compartment, an outer shell which houses the heat-producing substance and reaction, and a button by which the user can initiate the heating reaction. In some embodiments of the invention, a one-way valve connects the outer shell to the ambient atmosphere, allowing water vapor to escape the device. In other embodiments, water vapor is condensed back into the water reservoir chamber.

To warm contents of the container, the outer button is depressed, which opens a valve between the water reservoir and heat-producing substance. Such a substance would produce an exothermic reaction when hydrated, so the mixture of the two compartments would release heat to the internal contents of the container, thereby heating the contents. To reset the container for future uses, the device is placed in the microwave or oven to dehydrate the heat-producing substance, reversing the reaction and restoring the container to its original state. The water reservoir is refilled with water, and the container is again ready to be used to warm its contents with the push of a button.

Due to the need for the container to contact food and also be exposed to a wide range of temperatures, the materials for construction of the container need all be of food-grade quality, as determined by the Food and Drug Administration (FDA). In addition, because the container may be microwaved or placed in the oven to recharge the heat-producing substance, but could also be stored in the refrigerator, the materials of construction must be able to withstand a wide range of temperatures, especially high temperatures. In some embodiments of the invention, these construction materials could be a number of different food-grade silicone rubbers or other materials which meet the criteria outline above. In addition, all spring and valve-like components would also be made of temperature resistant, non-metallic materials to prevent sparking when heated.

CONTENTS COMPARTMENT

In all configurations of the invention there is at least one internal compartment 101 to hold the contents to be warmed, such as food, liquids, lotions, or towlettes. This compartment 101 can take on different sizes and shapes dependent on the intended use. Such a compartment can be seen in FIG. 1, which illustrates one possible embodiment of the invention. The wall of the contents compartment is made of a heat- and cold-resistant material to prevent damage due to frequent heating and cooling. The material should also be of food-grade quality for consumer safety. Water Reservoir:

All configurations of the invention also contain at least one internal compartment 301 for holding water, which is separated from the contents to be heated by internal walls 302, seen in the cut-out view in FIG. 3. There is an opening 102 at the top of the device above the water reservoir 301 for additional water to be added between uses. The water reservoir 301 is connected to the outer shell of the container 303 and heating substance 304 by a valve 501 which has a default position of closed to prevent mixture of the two compartments until it is desired, as illustrated in FIG. 5.

OUTER SHELL AND HEATING METHODS

An outer shell 303 surrounds the contents and water reservoir compartments of the invention. The outer shell is separated from the other compartments by internal walls 302, 306. In one embodiment of the invention, illustrated in FIG. 3, the outer shell is comprised of three layers: an outer wall made of thermally insulated material 305, an inner wall of the same food-grade resistant material that defines the internal compartments 306, and an internal space between the two walls which houses the heat-producing substance 304, which surrounds the internal compartments 101, 301. The water reservoir 301 is connected to the outer shell 303 via a valve 501, illustrated in FIG. 5 (for details, see FIG. 6). When the user depresses a button 103, a spring 502 engages and the valve 501 is opened, allowing water to flow into the internal space of the outer shell 304 and react with the heat-producing substance. This heat producing substance could be a number of different natural or synthetic zeolite materials that possess a strong affinity for water. Zeolites are aluminosilicate substances that undergo an exothermic reaction when hydrated. When water from the reservoir 301 enters the outer shell 303 and meets the zeolite or similar material, the zeolite is hydrated and an exothermic reaction occurs, giving off heat to the surroundings. This heat generation warms the internal contents of the container. The thermal insulation of the outer wall of the container 305 prevent the outside of the container from becoming too warm, and prevents heat loss outside the container, thereby improving heating of the internal contents. Zeolites are able to hydrate and dehydrate indefinitely while maintaining structural stability, allowing the heating reaction to be reversed and the container to be used to warm contents hundreds or thousands of times. In some embodiments of the invention, the zeolite or similar heating-producing substance is completely enclosed within the walls of the invention (see FIG. 3).

Additionally, due to the insulated outer layer of the container and the thermal mass of the container as a whole, the temperature of the invention will remain relatively constant even prior to warming. To this effect, it is possible that in some embodiments of the invention, such as in food storage, the self-warming container could be stored in the refrigerator prior to use, and the container would maintain its refrigerated temperature prior to the start of the warming process.

POWER BUTTON AND INITIATION MECHANISM

All configurations of the invention have a start button 103 which activates the warming container. The button 103 is comprised of two individual components, as seen in FIG. 2: a depressible button 201 and outer elastic covering 202. The button 201 and the elastic covering 202 could be different colored materials, such as a yellow button and a semi-transparent blue covering. In its initial state, the yellow button 201 and the blue covering 202 are both in the upper position and in close proximity to each other, as seen in FIG. 2 a. Because of the differing colors of the plastics, the button will appear one color to the user (in this instance, green). When the mechanism is depressed, initially both the button 201 and the covering 202 will be in the down position, but the elastic cover 202 will revert to its upper position due to its elasticity, as seen in FIG. 2 b. Because of the separation of the button 201 and elastic cover 202, the mechanism will now appear a different color to the user (in this case, blue).

Internally, the button connects to a spring 502 which runs the length of the water reservoir 301. This spring is connected at the opposite terminal to the valve 501 controlling the separation of the water reservoir and the heat-producing substance. When the user depresses the button 103, the spring engages the valve and opens the separation between the water reservoir and the heat-producing substance. In this manner, the user controls when the container begins to heat its contents by starting the heating reaction by pressing the button. Steam Releasing Valve:

In some embodiments of the invention, to reset the container after it is used for heating it must be placed in the microwave or oven to dehydrate the heat-producing material. During dehydration, the water which interacted with the heat producing material will be evaporated. To allow for this water vapor to escape the outer shell 303, a one-way valve 602 connects the inner space of the shell to the ambient atmosphere (see FIG. 6 for details). One possible embodiment of this valve is a spring-activated valve biasing the valve closed against the container. When the container is heated and enough water vapor produced, the vapor pressure overcomes the force of the spring and forces the valve 602 open to allow the vapor to escape. When the pressure is reduced after the elimination of water vapor, the spring seals the valve closed again to prevent moisture from the ambient air from interacting with the heat-producing substance 304. In still other embodiments, the water vapor may be vented back to the water reservoir 301 and condensed on the cooler walls of the compartment, rather than or in addition to venting to the ambient atmosphere.

HEATING CARTRIDGE DESIGN

In one embodiment of the invention, shown in FIGS. 7 and 8, the heating substance such as zeolites 702 could be enclosed in a removable and replaceable cartridge 703, rather than inherent to the device. In this way, the container could be used to warm many times by simply replacing a used heating cartridge with a recharged cartridge, rather than recharging the entire device in the microwave or oven, in cases where no such operation is possible. Rather, individual heating cartridges could be switched out when they have been used, and could be recharged in the microwave or oven after use. In such a design, the heating substance is present in an enclosed component which is separate from the main body of the container. The main body of the container could contain the main compartment to hold the contents to be warmed 701, the water reservoir 706 and associated start button and spring valve 707, and parts of the outer shell compartment 705. A separate cartridge houses the heating substance 702 in a completely enclosed compartment comprised of materials similar to those described above. When one desires to use the container, the cartridge is situated into the main container as seen in FIG. 7, in the outer shell area 704, 705 of the main container.

To connect the heating cartridge to the main container, there could be a moveable or pivoting portion of the main container outer wall 709, creating a door or port cover, which allows room for the cartridge to be positioned into place. This door or port cover would engage the cartridge and lock it in place, possibly via a spring-loaded mechanism. To provide continuity from the water reservoir in the main container 706 to the cartridge containing the heating material, there could be a junction 708 which allows the end of the heating cartridge to snap or fit up against the end of the water reservoir when it is positioned in the main container. Additionally, a removable barrier component 710 could be present in the heating cartridge to prevent external moisture from entering the heating substance 702 before the cartridge is positioned on the main container. The water-vapor release valve could be present in this heating cartridge, rather than on the main container as in other embodiments. 

1. An apparatus for warming substances comprising: a container, said container comprising a first compartment containing a substance that reacts exothermically with water; a second compartment containing water, wherein said second compartment is attached to said first compartment by a valve; and a third compartment, wherein at least 50% of the third compartment's volume is surrounded by said first compartment, and wherein said first and third compartments are separated by a thermally conductive wall.
 2. The apparatus of claim 1, wherein the substance that reacts exothermically with water is a zeolite.
 3. The apparatus of claim 2, further comprising a layer of insulating material that surrounds the surface of the first chamber opposite the third chamber.
 4. The apparatus of claim 2, further comprising a fourth compartment that surrounds the first compartment is substantially void of matter to create a vacuum insulating layer.
 5. The apparatus of claim 2, further comprising a one-way release valve attached to the first chamber, said one-way release valve capable of allowing water vapor to escape from the first chamber when the vapor pressure in the first chamber is greater than ambient pressure outside the container.
 6. The apparatus of claim 1, further comprising a layer of insulating material that surrounds the surface of the first chamber opposite the third chamber.
 7. The apparatus of claim 1, further comprising a fourth compartment that surrounds the first compartment is substantially void of matter to create a vacuum insulating layer.
 8. The apparatus of claim 1, further comprising a one-way release valve attached to the first chamber, said one-way release valve capable of allowing water vapor to escape the container from the first chamber when the vapor pressure in the first chamber is greater than ambient pressure outside the container.
 9. An apparatus for warming substances comprising: a container, said container including an outer shell, said container further comprising: a first compartment situated within the volume circumscribed by the outer shell; a second compartment situated within the volume circumscribed by the outer shell, wherein said second compartment is attached to said first compartment by a regulator; and a third compartment, wherein the third compartment's volume is partially bordered by said first compartment, and wherein said first and third compartments are separated by a thermally conductive wall; a heating material, situated within said first compartment, said heating material being a substance that reacts exothermically with water when in anhydrous form.
 10. The apparatus of claim 9, wherein the heating material is zeolite.
 11. The apparatus of claim 10, wherein the zeolite is an aluminosilicate.
 12. The apparatus of claim 9, further comprising an access door that is capable of opening to allow access to said first compartment.
 13. The apparatus of claim 12, wherein the heating material is contained within a removable cartridge that fits within said first compartment.
 14. A method for warming a substrate material comprising: placing said substrate material in a container, said container comprising a first chamber containing a material that reacts exothermically with water, a second chamber containing water; and a closed conduit connecting said first and second chambers; opening said closed conduit to introduce said water to said material that reacts exothermically with water, thereby initiating an exothermic reaction; and allowing said exothermic reaction to heat said substrate material.
 15. The method of claim 14, wherein said container is insulated.
 16. The method of claim 14, wherein the container has a volume of less than 10 liters.
 17. The method of claim 16, wherein the container has a volume of less than 5 liters.
 18. The method of claim 14, wherein the substrate material is food.
 19. The method of claim 14, wherein the heating material is a zeolite.
 20. The method of claim 19, further comprising heating the container and the zeolite until the zeolite has reverted to an anhydrous form. 